EnergyComparison

Efficiency of Common Devices

Part of EfficiencyGCSE Physics

This comparison covers Efficiency of Common Devices within Efficiency for GCSE Physics. Revise Efficiency in Energy for GCSE Physics with 19 exam-style questions and 4 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 5 of 13 in this topic. Use this comparison to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 5 of 13

Practice

19 questions

Recall

4 flashcards

⚖️ Efficiency of Common Devices

Device Input Energy Useful Output Efficiency
Incandescent bulb Electrical Light ~5%
LED bulb Electrical Light ~40–50%
Petrol car engine Chemical (fuel) Kinetic ~25%
Electric motor Electrical Kinetic ~90%
Solar panel Light (solar) Electrical ~15–22%
Human body (walking) Chemical (food) Kinetic ~25%

Keep building this topic

Read this section alongside the surrounding pages in Efficiency. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Efficiency

Which equation correctly defines efficiency?

  • A. efficiency = total input energy / useful output energy
  • B. efficiency = useful output energy transfer / total input energy transfer
  • C. efficiency = wasted energy / total input energy
  • D. efficiency = total input energy / wasted energy
1 markfoundation

Explain one method that can be used to reduce unwanted energy transfers in a machine and state how it reduces waste.

2 marksstandard

Quick Recall Flashcards

As a decimal
0.85 (between 0 and 1)
As a percentage
85% (multiply decimal by 100)

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